diff --git a/CLAUDE.md b/CLAUDE.md
index 7c498f7..3abef59 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -135,6 +135,7 @@ Use pyproject.toml with hatchling or setuptools as the build backend. Don't use
 
 ## Definition of Done
 
+- Implementation status updated in @README.md
 - Update tests to include new/changed work, aim for >80% code coverage, but prioritise good tests
 - Run tests and ensure they pass using `make ci`
 - If anything changed that would impact the notebooks, run `make execute-notebooks` to update their output
diff --git a/README.md b/README.md
index f45e655..ec2d17d 100644
--- a/README.md
+++ b/README.md
@@ -17,14 +17,19 @@ Handles 15-minute MTU resolution, rate limiting, response caching, timezone norm
 - **Type-safe** — strict mypy compliance, Pydantic v2 models
 - **No floats for money** — all prices and volumes use `Decimal`
 
-## Supported data sources
+## Status
 
-| Exchange | Data types |
+| Component | |
 |---|---|
-| Nord Pool | Day-ahead prices, intraday |
-| ENTSO-E | Day-ahead prices, generation (actual & forecast), load, cross-border flows |
-| EPEX SPOT | Day-ahead prices, intraday |
-| EEX | Futures, spot |
+| Nord Pool — day-ahead prices | ✅ |
+| Core types & exceptions | ✅ |
+| Unified `NexaClient` | 🚧 |
+| ENTSO-E client | ⬜ |
+| EPEX SPOT client | ⬜ |
+| EEX client | ⬜ |
+| Response caching | ⬜ |
+| Rate limiting | ⬜ |
+| Timezone normalisation | ⬜ |
 
 ## Installation